Centrifugal blower

ABSTRACT

An exemplary centrifugal blower is adapted for dissipating heat generated by an electronic component mounted on a printed circuit board. The centrifugal blower includes a housing defining a receiving space therein, and an impeller rotatably received in the housing. The impeller includes a hub, a supporting member fixed on the hub, and a plurality of blades extending outwardly from the supporting member. The blades are made of metal.

BACKGROUND

1. Technical Field

The present disclosure relates to centrifugal blowers, and more particularly to a centrifugal blower for dissipating heat generated by electronic components.

2. Description of Related Art

Generally, cooling fans are used in combination with heat sinks for cooling electronic components, such as CPUs. Most portable electronic systems that contain electronic components, such as laptop computers and notebook computers, have limited space therein. Thus a centrifugal blower which requires only a small space for installation is generally used in such electronic systems.

In use of the centrifugal blower, an impeller of the centrifugal blower rotates to generate airflow to the electronic component, thereby continuously taking away heat of the electronic component. Generally, the impeller comprises a plurality of blades which are made of polybutylene terephthalat (PBT). In order to improve the cooling and heat dissipation efficiency, the most direct and effective way is to increase the revolving speed of the impeller, thereby increasing the flow rate of the airflow. However, increasing the flow rate by increasing the rotating speed of the impeller incorporating PBT blades generally causes level of noise to be increased. This may annoy or cause discomfort to a user near the centrifugal blower.

What is needed, therefore, is a centrifugal blower which can overcome the above-described problems.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present centrifugal blower can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present centrifugal blower. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an assembled, isometric view of a centrifugal blower in accordance with an exemplary embodiment of the disclosure.

FIG. 2 is an inverted view of the centrifugal blower of FIG. 1.

FIG. 3 is an exploded view of the centrifugal blower of FIG. 1.

FIG. 4 is an inverted, exploded view of the centrifugal blower of FIG. 1.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a centrifugal blower in accordance with an exemplary embodiment of the disclosure is used for dissipating heat generated by an electronic component (not shown) mounted on a printed circuit board (not shown). The centrifugal blower comprises a housing 10, and an impeller 20 rotatably received in the housing 10.

Referring to FIGS. 3 and 4 also, the housing 10 is a hollow tank and defines a receiving space 15 accommodating the impeller 20 therein. The housing 10 comprises a base board 12, a covering board 11 located above the base board 12, and a sidewall 13 extending downwardly from an outer periphery of the covering board 11 to contact an outer periphery of the base board 12. In this embodiment, the sidewall 13 is integrally formed with the covering board 11 as one piece. A rectangular air outlet 16 is defined at a lateral side of the housing 10. The air outlet 16 is cooperatively defined by the covering board 11, the base board 12 and the sidewall 13. A circular first air inlet 111 is defined at a center of the covering board 11. A through hole 120 is defined at a center of the base board 12. A plurality of second air inlets 121 are defined at a central portion of the base board 12 and surround the through hole 120. The second air inlets 121 are spaced from each other. An annular rail 122 protrudes upwardly from the center of the base board 12 at an edge of the through hole 120.

The impeller 20 comprises a hub 21, a supporting member 22 fixed on the hub 21, and a plurality of blades 23 extending outwardly from the supporting member 22. The hub 21 has a cylindrical configuration. The hub 21 comprises a circular body 211, and an annular wall 212 extending perpendicularly and downwardly from a periphery of the circular body 211. The circular body 211 of the hub 21 is rotatably disposed on the annular rail 122. The supporting member 22 comprises a hollow main body 221 fixed on and encircling the hub 21, a fixing ring 222 encircling the main body 221, and a plurality of spaced arms 223 interconnecting the main body 221 and the fixing ring 222. The main body 221 has a cylindrical configuration. The fixing ring 222 is concentric with the main body 221. The blades 23 are fixed to the fixing ring 222 of the supporting member 22. The blades 23 are arranged radially relative to the main body 221 and the hub 21. The blades 23 are made of metal, preferably, the blades 23 are made of magnesium aluminum alloy. Since the blade 23 is metal, a strength of the blade 23 is enhanced, when the blade 23 is made of magnesium aluminum alloy, a weight of the blade 23 is further lighten compared with that of the blade 23 made of aluminum. Thus the blade 23 can be made thinner, and an amount of the blades 23 of the impeller 20 can be increased with respect to conventional impeller incorporating PBT blades with the same size. Generally, a thickness of each blade 23 is less than 0.5 mm, preferably, the thickness of each blade 23 is 0.3 mm. Each of the blades 23 has an arced configuration. In this embodiment, each of the blades 23 is an arced metal sheet, and comprises a first portion (not labeled) engaging with the fixing ring 222 and a second portion (not labeled) extending outwards from the first portion. The first portion has a height larger than that of the second portion along an axial direction of the fixing ring 222, an upper part of the first portion extends upwards beyond the second portion. The first portion of each blade 23 defines a lateral slit (not labeled). The fixing ring 222 engages into the slit. A lateral end part of the slit has a depth smaller than a thickness of the fixing ring 222, so that the fixing ring 222 firmly engages with the blades 23 and can not break loose from the slit.

Following table shows performance of the impeller 20 compared with that of a conventional impeller which incorporates blades made of polybutylene terephthalat (PBT).

Rotating Air speed Blade pressure Air flow Noise Blade material (rpm) numbers (mmAq) (cfm) (dBA) polybutylene 4700 37 11.87 2.00 37.3 terephthalat magnesium 4700 41 16.61 2.31 38.0 aluminum alloy

It can be concluded from the above table, the impeller has four blades more than the conventional PBT blade impeller with the same size, and accordingly the impeller 20 of the present disclosure has greater air pressure and air flow than the conventional impeller when rotating at the same speed. In addition, since the metal blades have enhanced strength, the impeller 20 with higher air pressure has a level of noise substantially equal to the conventional impeller.

During operation, the impeller 20 is driven by a stator (not shown) of the centrifugal blower to be rotatable with respect to the stator in the housing 10. As the impeller 20 rotates, the blades 23 force the air adjacent to the first air inlet 111 and second air inlet 121 into the housing 10. The air then flows along the sidewall 13 to the air outlet 16 to generate high-pressure airflow toward the electronic component which needs to be cooled.

It is to be understood, however, that even though numerous characteristics and advantages of the present embodiment(s) have been set forth in the foregoing description, together with details of the structures and functions of the embodiment(s), the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A centrifugal blower, comprising: a housing defining a receiving space therein; and an impeller rotatably received in the housing, the impeller comprising a hub, a supporting member fixed on the hub, and a plurality of blades extending outwardly from the supporting member, and the blades being made of metal.
 2. The centrifugal blower of claim 1, wherein the blades are made of magnesium aluminum alloy.
 3. The centrifugal blower of claim 1, wherein the housing comprises a base board, a covering board located above the base board, a sidewall extending downwardly from an outer periphery of the covering board to contact an outer periphery of the base board.
 4. The centrifugal blower of claim 3, wherein a first air inlet is defined at a center of the covering board.
 5. The centrifugal blower of claim 3, wherein a plurality of second air inlets are defined at a central portion of the base board.
 6. The centrifugal blower of claim 3, wherein an air outlet is defined at a lateral side of the housing.
 7. The centrifugal blower of claim 1, wherein the blades are arranged radially relative to the hub.
 8. The centrifugal blower of claim 1, wherein each blade has an arced configuration.
 9. The centrifugal blower of claim 1, wherein a thickness of each blade is smaller than 0.5 mm.
 10. The centrifugal blower of claim 9, wherein the thickness of each blade is 0.3 mm.
 11. The centrifugal blower of claim 1, wherein the supporting member comprises a hollow main body fixed on and encircling the hub, a fixing ring encircling the main body, and a plurality of spaced arms interconnecting the main body and the fixing ring.
 12. The centrifugal blower of claim 11, wherein the blades are fixed to the fixing ring.
 13. The centrifugal blower of claim 12, wherein the blades each define a lateral slit, the fixing ring engaging into the slits of the blades.
 14. An impeller, comprising: a housing; and an impeller rotatably received in the housing, the impeller comprising a hub, and a plurality of blades surrounding the hub, and the blades being made of magnesium aluminum alloy.
 15. The centrifugal blower of claim 14, wherein the housing comprises a base board, a covering board located above the base board, a sidewall extending downwardly from the covering board and interconnecting outer peripheries of the covering board and the base board.
 16. The centrifugal blower of claim 15, wherein a first air inlet is defined at a center of the covering board, and a second air inlet are defined at the base board opposite to the first air inlet.
 17. The centrifugal blower of claim 15, wherein an air outlet is defined at a lateral side of the housing.
 18. The centrifugal blower of claim 14, wherein the blades each comprise a first portion and a second portion extending from the first portion, the first portion having a height larger than that of the second portion along an axial direction of the impeller.
 19. The centrifugal blower of claim 14, wherein each blade has an arced configuration.
 20. The centrifugal blower of claim 14, wherein the thickness of each blade is 0.3 mm. 